1. Field of the Invention
The present invention relates to a terminal, such as a portable telephone, and more particularly, to a SIM (Subscriber Identity Module) card storing subscriber-related information data, which is located within a battery pack of the terminal, preferably being detachably inserted into the terminal.
2. Description of the Related Art
There are three general digital cellular systems, namely GSM (Global System for Mobile) which is a European TDMA (Time Division Multiple Access) system, NA-TDMA (North American TDMA), and CDMA (Code Division Multiple Access).
GSM is an international standard, offering compatibility throughout diverse telecommunications networks and has been implemented in Europe and countries in other continents.
A terminal in the GSM system includes a SIM card. The SIM card stores most of the information needed for operating a terminal, including data representing a telephone number, a network number, and subscriber information, such as subscriber ID.
SIM cards are available in two types, namely a postage stamp type (see U.S. Pat. No. 5,320,552) and a credit card type. The postage stamp type SIM card is detachably inserted into a SIM card contact device after a battery pack is removed from the body of the terminal. The SIM card contact device is then mounted onto the terminal body.
Conventional SIM cards, regardless of their type, typically occupy a relatively large area, which is contradictory to the current trend toward manufacturing more compact, lightweight terminals.
In the postage stamp type SIM card, a SIM card reader is installed on a main PCB(Printed Circuit Board) of a body and the SIM card is electrically connected to the SIM card reader by means of a SIM card contact device. Consequently, the SIM card reader and contact device occupy a relatively large area on the body of the terminal, limiting the compactness of the terminal body, thereby decreasing product competitiveness.
In the credit card type SIM card, the SIM card is pushed between the terminal body and a battery pack for installation, resulting in decreased contact reliability and also presenting an inconvenience to the user.